Gouge stability controlled by temperature elevation and obsidian addition in basaltic faults and implications for moonquakes

Basalt is a major component of the earth and moon crust.Mineral composition and temperature influence frictional instability and thus the potential for seismicity on basaltic faults.We performed velocitystepping shear experiments on basalt gouges at a confining pressure of 100 MPa,temperatures in the range of 100-400℃ and with varied obsidian mass fractions of 0-100%under wet/dry conditions to investigate the frictional strength and stability of basaltic faults.We observe a transition from velocity-neutral to velocity-weakening behaviors with increasing obsidian content.The frictional stability response of the mixed obsidian/basalt gouges is characterized by a transition from velocitystrengthening to velocity-weakening at 200℃ and another transition to velocity-strengthening at temperatures>300℃.Conversely,frictional strengths of the obsidian-bearing gouges are insensitive to temperature and wet/dry conditions.These results suggest that obsidian content dominates the potential seismic response of basaltic faults with the effect of temperature controlling the range of seismogenic depths.Thus,shallow moonquakes tend to occur in the lower lunar crust due to the corresponding anticipated higher glass content and a projected temperature range conducive to velocity-weakening behavior.These observations contribute to a better understanding of the nucleation mechanism of shallow seismicity in basaltic faults.

J-TEXT achievements in turbulence and transport in support of future device/reactor

Following the reconstruction of the TEXT tokamak at Huazhong University of Science and Technology in China, renamed as J-TEXT, a plethora of experimental and theoretical investigations has been conducted to elucidate the intricacies of turbulent transport within the tokamak configuration. These endeavors encompass not only the J-TEXT device's experimental advancements but also delve into critical issues pertinent to the optimization of future fusion devices and reactors. The research includes topics on the suppression of turbulence, flow drive and damping, density limit, non-local transport, intrinsic toroidal flow, turbulence and flow with magnetic islands, turbulent transport in the stochastic layer, and turbulence and zonal flow with energetic particles or helium ash. Several important achievements have been made in the last few years, which will be further elaborated upon in this comprehensive review.

Self-supported ultrathin NiCo layered double hydroxides nanosheets electrode for efficient electrosynthesis of formate

Electrochemical CO_(2)reduction into energy-carrying compounds,such as formate,is of great importance for carbon neutrality,which however suffers from high electrical energy input and liquid products crossover.Herein,we fabricated self-supported ultrathin NiCo layered double hydroxides(LDHs)electrodes as anode for methanol electrooxidation to achieve a high formate production rate(5.89 mmol h^(-1)cm^(-2))coupled with CO_(2)electro-reduction at the cathode.A total formate faradic efficiency of both anode for methanol oxidation and cathode for CO_(2)reduction can reach up to 188%driven by a low cell potential of only 2.06 V at 100 mA cm^(-2)in membrane-electrode assembly(MEA).Physical characterizations demonstrated that Ni^(3+)species,formed on the electrochemical oxidation of Ni-containing hydroxide,acted as catalytically active species for the oxidation of methanol to formate.Furthermore,DFT calculations revealed that ultrathin LDHs were beneficial for the formation of Ni^(3+)in hydroxides and introducing oxygen vacancy in NiCo-LDH could decrease the energy barrier of the rate-determining step for methanol oxidation.This work presents a promising approach for fabricating advanced electrodes towards electrocatalytic reactions.

A federated learning scheme meets dynamic differential privacy

Federated learning is a widely used distributed learning approach in recent years,however,despite model training from collecting data become to gathering parameters,privacy violations may occur when publishing and sharing models.A dynamic approach is pro-posed to add Gaussian noise more effectively and apply differential privacy to federal deep learning.Concretely,it is abandoning the traditional way of equally distributing the privacy budget e and adjusting the privacy budget to accommodate gradient descent federation learning dynamically,where the parameters depend on computation derived to avoid the impact on the algorithm that hyperparameters are created manually.It also incorporates adaptive threshold cropping to control the sensitivity,and finally,moments accountant is used to counting the∈consumed on the privacy‐preserving,and learning is stopped only if the∈_(total)by clients setting is reached,this allows the privacy budget to be adequately explored for model training.The experimental results on real datasets show that the method training has almost the same effect as the model learning of non‐privacy,which is significantly better than the differential privacy method used by TensorFlow.

面向CO_(2)电化学转化的铜基催化剂研究进展

化石燃料的大量使用造成大气中CO_(2)含量不断上升,带来了一系列气候及环境问题。将温室气体CO_(2)进行捕集并转化利用有助于缓解能源短缺和全球变暖等问题,其中电化学技术因其具有温和可控的工作条件以及与可再生能源的相容性等特点,成为了一种很有前景的CO_(2)转化利用技术。铜催化剂因其在电化学还原CO_(2)过程中可以产生高价值的碳氢化合物而受到广泛关注与研究,但是有效产物的选择性依然较低,特别是C_(2+)物种。因此提高铜基催化剂表面产物选择性成为了该领域研究难点与热点。为此,本文主要介绍了近五年不同改性方式的Cu基催化剂在选择性制备C_(2+)产物方面的研究进展,概述了可能的反应机理并且总结了影响产物选择性的因素,最后提出了该领域进一步的研究方向与展望。

云南省文山州40岁及以上壮族和苗族人群翼状胬肉患病率及其影响因素

目的:调查云南省文山州40岁及以上壮族和苗族人群的翼状胬肉患病率及其影响因素。方法:采用手持式裂隙灯和Keratograph-D眼表综合分析仪对云南省壮族和苗族目标人群进行流行病学调查,采用Logistic回归分析研究性别、年龄、职业、是否户外活动和民族等因素对翼状胬肉的影响。结果:于2019-03/11选取调查对象共1239人,确诊翼状胬肉437人,翼状胬肉总体患病率为35.27%。双眼翼状胬肉占59.27%,单眼翼状胬肉占40.73%。胬肉患病率在壮族人群为34.84%(224人),在苗族人群为35.74%(213人),两者无差异(P=0.740)。Logistic回归分析结果显示,睑板腺开口有无堵塞是翼状胬肉发生的影响因素(P=0.019),优势比OR=1.348。性别、年龄、受教育程度、是否户外活动、高血压和饮食习惯不是翼状胬肉的影响因素。用等级资料的Logistic回归进行胬肉侵入程度的多因素分析,结果显示泪河高度是翼状胬肉侵入程度的影响因素(P=0.048),泪河高度值越低,侵入程度越大。结论:云南省文山州40岁及以上壮族和苗族人群翼状胬肉患病率较高,睑板腺开口有无堵塞、泪河高度影响翼状胬肉的发生和侵入程度。

Selective recovery of zinc from zinc oxide dust using choline chloride based deep eutectic solvents

Deep eutectic solvents(DESs) are a kind of potential lixiviant for selective metal processing due to their versatile complexation properties. In this study, we investigated the recovery of zinc from zinc oxide dust using choline chloride-ureaethylene glycol(ChCl-urea-EG) DESs. The zinc extraction efficiency can be up to 85.2% when the slurry concentration is 50 g/L, leaching temperature is 80 °C and stirring speed is 600 r/min. The leaching process is controlled by the diffusion and the corresponding activation energy is 32.1 k J/mol. The resultant solution was directly used for the electrodeposition of zinc. The pure zinc deposit is obtained with a current efficiency of 82.6%. Furthermore, the ChCl-urea-EG DESs can be recycled. This approach is shown to be promising for the recycling of zinc from the zinc-containing dust.

Recent Advances on Citrus yellow vein clearing virus in Citrus

Citrus yellow vein clearing virus(CYVCV)is the causal agent of yellow vein clearing disease,a significant and devastating disease of most citrus species including lemon and sour orange.CYVCV,a single-strand positive-sense RNA virus containing six ORFs(Open Reading Frames),represents a new species in the genus Mandarivirus of the Alphaflexiviridae family.The virus can cause particularly serious damage,resulting in reduced tree vigor,lower yields,and decreased marketability of fruit production,and it has been found in India,Turkey,Pakistan,China and Iran.Here we described the geographical distribution of the virus,its transmission mode by grafting,mechanical inoculation,and insects,as well as currently available techniques for detection.In addition,we also discussed practical measures aimed at controlling the disease and provided theoretical guidance to prevent the acquisition and spread of the disease that is a significant step toward ensuring the health of the citrus industry.

Tuning the electronic structure of platinum nanocrystals towards high efficient ethanol oxidation

Direct ethanol fuel cell is a promising low temperature fuel cell,but its development is hindered by sluggish kinetics of anode catalysts for ethanol oxidation.Here a high efficient platinum/tin oxide/Graphene nanocomposite is synthesized through a facile and environmentally benign method.The structure and morphology are carefully characterized by X-ray diffraction and Transmission electron microscopy,showing a clear platinum/tin oxide heterostructure uniformly dispersed on graphene support.This catalyst demonstrates the highest activity among the reported catalysts and much higher durability towards ethanol oxidation compared to conventional platinum nanocatalysts.The ultrahigh activity originates from promoted removal of poisoning carbon monoxide immediate species on platinum due to a strong electronic donating effect from both tin oxide and graphene,which is fully supported by carbon monoxide stripping and X-ray photoelectron spectroscopy analysis.Our platinum/tin oxide/Graphene appears to be a promising candidate for ethanol oxidation electrocatalysts.

Toroidal component of velocity for geodesic acoustic modes in the edge plasmas of the J-TEXT tokamak

The toroidal component of the velocity for geodesic acoustic modes(GAMs)is first demonstrated.Multiple Langmuir probe arrays set up near the top tokamak of the J-TEXT were utilized for this study.A significant peak at the GAM frequency is observed in Mach number fluctuations.The toroidal velocity for the GAMs is estimated as 10–100 ms-1 and increases with the poloidal velocity.The ratio of toroidal component to the poloidal one of the velocity is mainly located in the interval between 0.3 and 1.0.With higher safety factors q,the ratio almost does not change with decreasing the safety factor,whereas it goes up sharply at low q.The coherencies between poloidal electric fields and Mach number fluctuations in turbulence frequency bands are also evaluated,and are higher than those between radial electric fields and Mach number fluctuations.

尖晶石钴氧化物的晶面调控与析氧活性研究

由可再生能源驱动的水分解是一种有前途的生产清洁能源的技术,而发生在阳极的析氧反应是水分解反应的速率决定步骤。本文通过调整催化剂的晶面,暴露更多的有效活性位点调控尖晶石钴氧化物析氧反应活性。在三个合成晶面(100)、(111)和(110)中,(100)晶面本征活性最高。结合原位红外和DFT计算分析可知,OER反应在氧化钴晶体的(100)平面上反应能垒最低。XPS分析进一步表明,纳米立方体表面具有最高的Co^(3+)/Co^(2+)比值,该结果表明Co^(3+)是更活跃的析氧反应活性位点。

First-principles study on the mechanical properties and thermodynamic properties of Mo-Ta alloys

The mechanical properties,thermodynamic properties and electronic structure of Mo1-xTax(Mo-Ta)alloys(x=0,0.0625,0.125,0.25,0.3125,0.5 and 1)were calculated by using firstprinciples.The electronic structure of Mo-Ta alloys was analysed by the projected density of states(PDOS).The low temperature heat capacity was estimated by Fermi energy and Debye temperature.It is shown that the formation enthalpy will decrease with the increase of Ta content,and the cohesive energy will increase with the increase of the Ta content.On the other hand,the addition of Ta atoms will reduce the strength and improve the ductility of Mo-Ta alloys,the Debye temperature will decrease and the low temperature heat capacity will be improved with the increase of the Ta content.All these results will be useful for the research of new plasma grid(PG)materials,which is mainly used in neutral beam injection(NBI)systems to produce negative hydrogen ions.

A Localized Inter-Actuator Network Topology Repair Scheme for Wireless Sensor and Actuator Networks

Node failure is one of the most severe problems that wireless sensor and actuator networks(WSANs) have to deal with. The failure of actuator nodes, in particular, may result in substantial consequences such as network partitioning, incorrect and incomplete decision execution for WSANs. This paper proposes an efficient localized scheme, called LANTR, to repair the damaged topology of inter-actuator network while single actuator node paralyzes. For the failure of an ordinary actuator node, LANTR can rapidly repair the topology through relocating only one-hop neighbors of the failure node, meanwhile, keep the original topology structure as much as possible. Given the magnitude of cut vertex actuators playing on the connectivity, LANTR designs a novel method for each cut vertex to select out a specific guardian node with the minimum degree or minimum cumulative degree from its neighbors, which can reduce the repair influence on the original topology and effectively reduce the coverage loss rate. The performance of the proposed scheme is evaluated and compared with several existing representative topology repair schemes, and the results indicate that LANTR can more effectively and efficiently repair the topology of inter-actuator networks.

The application of limiter target electrostatic measurement system in J-TEXT tokamak

The limiter target electrostatic measurement system including limiter grounding current sensors and Langmuir probes have been newly developed for the measurement of the limiter target area on the Joint-Texas Experimental tokamak (J-TEXT). Current sensors fixed between graphite limiters and the vacuum vessel walls are used to measure the currents between limiters and vessel wall. Simultaneously, a rectangular poloidal array containing 54 Langmuir probes is embedded in the graphite tiles of limiters for a more localized measurement. Based on this system, the effect of both the plasma’s inherent behavior, including plasma motion and the 2/1 tearing mode, and the electrode biasing on probe and sensor signals have been observed and analyzed in the experiments.

Surface,Size and Thermal Effects in Alkali Metal with Core-Electron Binding-Energy Shifts

Consistency between density functional theory calculations and X-ray photoelectron spectroscopy measurements confirms our predications on the undercoordination-induced local bond relaxation and core level shift of alkali metal,which determine the surface,size and thermal properties of materials.Zone-resolved photoelectron spectroscopyanalysis method and bond order-length-strength theory can be utilized to quantify the physical parameters regarding bonding identities and electronic property of metal surfaces,which allows for the study of the core-electron binding-energy shifts in alkali metals.By employing these methods and first principle calculation in this work,we can obtain the information of bond and atomic cohesive energy of under-coordinated atoms at the alkali metal surface.In addition,the effect of size and temperature towards the binding-energy in the surface region can be seen from the view point of Hamiltonian perturbation by atomic relaxation with atomic bonding.

Revisiting Chlor-Alkali Electrolyzers:from Materials to Devices

As an energy-intensive industry,the chlor-alkali process has caused numerous environmental issues due to heavy electricity consumption and pollution.Chlor-alkali industry has been upgraded from mercury,diaphragm electrolytic cell,to ion exchange membrane(IEM)electrolytic cells.However,several challenges,such as the selectivity of the anodic reaction,sluggish kinetics of alkaline hydrogen evolution,degradation of membranes,the reasonable design of electrolytic cell structure,remain to be addressed.For these reasons,this paper mainly reviews the research progress of the chlor-alkali industry from materials to devices,including hydrogen evolution anode,chlorine evolution cathode,IEM,and electrolytic cell system.Finally,the research directions and prospects in the chlor-alkali industry are proposed for its further improvement.

Lightweight Frame Topology Optimization Method Based on Multi-objective

The application of new materials is an important direction for automotive lightweighting.On the basis of ensuring the comprehensive performance of components,the optimization of new material structures through topology optimization methods can further improve the level of lightweight components.This paper takes the automobile frame as the research object,based on the magnesium alloy,studies the frame topology with the objective function of mass and strength under multiple working conditions,and realizes the lightweight of the automobile frame structure through the multi-objective topology optimization method.According to the topological optimization method of penalty function for solid isotropic materials,the objective function of the quality topology optimization and the objective function of intensity topology optimization under multi-operating conditions are defined by the compromised programming approach.This method avoids the disadvantage that single-target topology optimization cannot consider other factors and is suitable for multi-objective topology optimization of continuum structures.

Analysis of Physical and Chemical Indices and Quality of Blueberry Wines from Gardenblue and Baldwin

Gardenblue and baldwin rabbiteye blueberry are the alien varieties. The physical and chemical indices of the fresh fruits of the two varieties were analyzed. The results showed that the sugar-acid ratio was higher in gardenblue than in baldwin, and the content of anthocyanins was also higher in gardenblue than in baldwin, so the quality of gardenblue was better. The gardenblue wine has better quality than the baldwin wine, and the two kinds of wines both have good quality. Therefore, gardenblue and baldwin both are suitable for the brewing red wine as the raw material.

Sourcing the merits of 3D integrated air cathodes for highperformance Zn-air batteries by bubble pump consumption chronoamperometry

Zn-air batteries(ZABs)as a potential energy conversion system suffer from low power density(typically≤200 mW·cm^(−2)).Recently,three-dimensional(3D)integrated air cathodes have demonstrated promising performance over traditional twodimensional(2D)plane ones,which is ascribed to enriched active sites and enhanced diffusion,but without experimental evidence.Herein,we applied a bubble pump consumption chronoamperometry(BPCC)method to quantitatively identify the gas diffusion coefficient(D)and effective catalytic sites density(ρEC)of the integrated air cathodes for ZABs.Furthermore,the D andρEC values can instruct consequent optimization on the growth of Co embedded N-doped carbon nanotubes(CoNCNTs)on carbon fiber paper(CFP)and aerophilicity tuning,giving 4 times D and 1.3 timesρEC over the conventional 2D Pt/C-CFP counterparts.As a result,using the CoNCNTs with half-wave potential of merely 0.78 V vs.RHE(Pt/C:0.89 V vs.RHE),the superaerophilic CoNCNTs-CFP cathode-based ZABs exhibited a superior peak power density of 245 mW·cm^(−2) over traditional 2D Pt/C-CFP counterparts,breaking the threshold of 200 mW·cm^(−2).This work reveals the intrinsic feature of the 3D integrated air cathodes by yielding exact D andρEC values,and demonstrates the feasibility of BPCC method for the optimization of integrated electrodes,bypassing trial-and-error strategy.

Prediction of surface settlement caused by synchronous grouting during shield tunneling in coarse-grained soils:A combined FEM and machine learning approach

This paper presents a surrogate modeling approach for predicting ground surface settlement caused by synchronous grouting during shield tunneling process.The proposed method combines finite element simulations with machine learning algorithms and introduces an intelligent optimization algorithm to invert geological parameters and synchronous grouting variables,thereby predicting ground surface settlement without conducting numerous finite element analyses.Two surrogate models based on the random forest algorithm are established.The first is a parameter inversion surrogate model that combines an artificial fish swarm algorithm with random forest,taking into account the actual number and distribution of complex soil layers.The second model predicts surface settlement during synchronous grouting by employing actual cover-diameter ratio,inverted soil parameters,and grouting variables.To avoid changes to input parameters caused by the number of overlying soil layers,the dataset of this model is generated by the finite element model of the homogeneous soil layer.The surrogate modeling approach is validated by the case history of a large-diameter shield tunnel in Beijing,providing an alternative to numerical computation that can efficiently predict surface settlement with acceptable accuracy.